Short answer: impact windows use laminated glass in a reinforced frame, tested as a unit so the opening stays sealed when debris hits it. In Port St. Lucie they replace storm shutters and cost an estimated $800–$2,100 per standard-size window installed.
Why most Port St. Lucie homeowners pick impact glass
Under the Florida Building Code, window openings on Port St. Lucie homes need protection from wind-borne debris. The city's permit form asks whether new windows are impact-rated, and notes that non-impact windows may need a separate shutter permit. You can meet the rule with shutters, but they have to be stored, put up before every storm and taken down after it. Impact windows protect the opening all season with nothing to install, which is why most replacement jobs here go that route.
How an impact window works
An impact unit is two panes of glass bonded to a tough plastic interlayer, set in a heavier frame. When something hits it, the glass may crack, but the interlayer holds it in place and the frame keeps it anchored to the wall. The glass, frame, hardware and anchors are tested together, which is why the rating belongs to the whole assembly, not just the glass.
The two numbers to check on any quote
- Florida Product Approval (FL#). Every impact window sold for a permitted Florida job carries a state approval number. The City of Port St. Lucie permit application asks for it, and you can look it up on the Florida Building Commission's website.
- Design pressure (DP). The pressure rating the window must meet for its specific opening, set by the wind speed, the house height and where the window sits on the wall. Corner openings usually need a higher rating.
Insurance and wind mitigation
Florida law requires home insurers to offer credits for wind-resistant features, and a wind mitigation inspection records whether every opening is protected. Impact windows on all openings can move that part of the inspection up a category. Keep your permit, the product approvals and the final inspection; the inspector will ask for them.
Paying for it: grants and the tax refund
- Sales tax refund. A 2026 Florida law refunds up to $500 of the sales tax paid on impact-resistant windows and doors bought between July 1, 2026 and June 30, 2029, for homesteaded houses with a just value of $700,000 or less. You apply to the Florida Department of Revenue.
- My Safe Florida Home. The state program has offered grants toward impact windows and doors for eligible homesteaded houses after a free wind mitigation inspection. Funding opens and closes, so check current availability before counting on it.
Installation in block homes
Block walls are common in Port St. Lucie; the city's permit form calls inset installation the usual method for them, versus a nailing-fin install on wood-frame walls. The new frame is anchored into the block or the wood buck around the opening using the fastener pattern in the product approval. If the old frame comes out fully, expect some stucco patching and paint around the opening. That work, and any rotten buck replacement, should be itemized on the quote.
Impact window questions
What is the difference between impact windows and hurricane windows?
In Port St. Lucie the two names mean the same thing: a window whose glass and frame were tested together to resist wind-borne debris and storm pressure. Ask for the Florida Product Approval number rather than relying on the label.
Can impact glass break?
It can crack. The laminated layer is there to hold the broken glass in the frame so the opening stays closed and wind and rain stay out. It is storm-resistant, not unbreakable.
Do impact windows lower home insurance?
They can. Florida insurers are required to offer wind mitigation credits, and protected openings are one of the items a wind mitigation inspection records. The size of any discount depends on your insurer and the rest of the house, so ask your agent.
Do I need impact glass on every window?
To get the full benefit, every opening needs protection: impact glass or approved shutters. Mixing impact windows with shutters on the rest is allowed and can phase the cost.
How long do impact windows take to get?
Impact windows are made to the measured size of each opening, so factory lead time is the longest part. Lead times swing with demand, especially after a storm, so ask for a current estimate on the quote.